This invention relates generally to telecommunication systems and more particularly to telecommunication systems adapted for used with Internet, Intranet, Extranet TCP/IP network protocol.
As is known in the art, Internet, Intranet, Extranet networks (referred to herein as IP networks) have supplemented public service telephone networks (PSTNs) in providing telephony services. For example, client software is available for enabling an Internet subscriber to place calls to a called party through the Internet. Typically, the calling party accesses the Internet via an Internet Service Provider (ISP) through either a modem or a local area network (LAN) router. Data is transmitted from the calling party's ISP through the Internet using an Internet protocol, typically the Transmission Control Protocol (TCP) and the Internet Protocol (IP) commonly referred to collectively as TCP/IP. This TCP/IP protocol is also used for Intranets/Extranets serving a specific closed group of subscribers/users. Thus, the term IP network will be used to include any network using the TCP/IP network protocol. The routing of information through an IP network is based on TCP/IP addressing. A TCP/IP address is 32 bits long and is commonly expressed as four decimal numbers-ranging from 0 to 256, with each number separated by a dot.
As is also known in the art, when accessing the ISP with a modem, the ISP makes available a modem in a modem pool in what is sometimes referred to as a "point-to-point" protocol. When accessing the ISP with a direct leased line, as from a LAN or cable company (CATV), data packets transfer between the LAN or cable and the IP network directly as IP packets of information. The routing through the IP network is, as noted above, using the TCP/IP network protocol with each point on the IP network having a TCP/IP address. A router server is coupled to the IP network to convert between an E.164 telephone number (i.e., using a central office addressing protocol) and TCP/IP address (i.e., the IP TCP/IP network addressing protocol). Thus, for example, if a cable-based IP user wishes to call a called party on the PSTN network, the calling party dials the called party's E.164 directory number, the router server converts the dialed number to an TCP/IP number, the call is routed through the cable-based IP network to the TCP/IP address of an ISP gateway which then converts the TCP/IP address to the called party's E.164 directory telephone number and directs the call through the central office on one of the lines (i.e., a trunk line) into the central office.
As is also known in the art, a variety of services, or features, are available to subscribers of the PSTNs. For residential PSTN subscribers, these features include: Plain Old Telephone Service (POTS); custom calling features (such as, call waiting, call forwarding, three-way calling, and speed calling, for example); advanced calling features (such as, called ID); Advanced Services for Display-Based Telephone Sets (ADSI); Digital Voice and Data on One Line (ISDN); Voice-Activated Services; Operator Services; and Voice Mail. For business PSTN subscribers, these feature include: ISDN Line-Level Interface (BRI); ISDN High-Bandwidth Trunk Interface (PRI); Centrex Business Telephone Groups; Automatic Call Distribution (ACD); Frame Relay Data Transmission; Videoconferencing; and Dialable Wideband Services/Bandwidth on Demand. A list of the features subscribed to are stored in a "features" database at the central office connected to the PSTN subscriber (i.e., the subscriber's central office, end office, or local switch). Thus, when a calling party goes "off-hook", the central office returns a dial-tone and then the calling party enters a called party's digits. A processor at the central office addresses the "features" database (and an administration database, for billing, etc.) using the calling party's telephone number, known as the calling party's E.164. The central office processor reads the called digits and provides switching signals to a central office switching network to route the call to the called party with the calling party having available the subscribed features stored in the "features" database. It is noted that the central office communicates internally and with other central offices in the PSTN with protocols (i.e., protocols adapted for use with analog (POTS), ISDN, and PBX, for example) which are different from the TCP/IP network protocol.